By May 2008, as the price of crude oil and gas spiked, margins on SemGroup's options contracts rose. On May 21 of that year, according to the suit, J. Aron told SemGroup to expect a margin call of $80 million to $100 million.

J. Aron and SemGroup agreed to an arrangement where SemGroup would buy large amounts of oil and gas from the Kansas and Oklahoma plaintiffs and deliver it to J. Aron as collateral, even though it knew SemGroup didn't have the cash available to pay for it, according to the suit. Payment for the oil and gas typically was not due to the producers for 50 days after the delivery.

But SemGroup's financial situation deteriorated and, on July 21, J. Aron notified SemGroup that it was in default on the options margins and foreclosed on the producers' oil and gas.

The suit contends British Petroleum also took oil from SemGroup in lieu of money owed by SemGroup, without actually paying for it.

But, said Kyle Lonergan, the producers' New York attorney, Kansas and Oklahoma law gives the producers a lien on the oil that was never cleared.

"The defendants never paid for the oil," Lonergan said. "Our clients are entitled to the proceeds from their production."

Representatives of Goldman Sachs and British Petroleum declined to comment.